[....] Starting file context maintaining daemon: restorecond[?25l[?1c7[1G[[32m ok [39;49m8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[ 16.161682] random: sshd: uninitialized urandom read (32 bytes read, 32 bits of entropy available) [?25l[?1c7[1G[[32m ok [39;49m8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 20.560731] random: sshd: uninitialized urandom read (32 bytes read, 37 bits of entropy available) [ 20.834786] random: sshd: uninitialized urandom read (32 bytes read, 37 bits of entropy available) [ 21.715218] random: sshd: uninitialized urandom read (32 bytes read, 105 bits of entropy available) [ 21.896962] random: sshd: uninitialized urandom read (32 bytes read, 111 bits of entropy available) Warning: Permanently added '10.128.0.49' (ECDSA) to the list of known hosts. [ 27.291014] random: sshd: uninitialized urandom read (32 bytes read, 119 bits of entropy available) executing program [ 27.383940] ================================================================== [ 27.391328] BUG: KASAN: use-after-free in __lock_acquire+0x387e/0x4b50 [ 27.397966] Read of size 8 at addr ffff8800b452e338 by task syzkaller122217/3318 [ 27.405463] [ 27.407062] CPU: 0 PID: 3318 Comm: syzkaller122217 Not tainted 4.4.112-g5f6325b #28 [ 27.414829] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 27.424156] 0000000000000000 1df7b856bd7928f6 ffff8801d0d8f8d0 ffffffff81d0579d [ 27.432120] ffffea0002d14b80 ffff8800b452e338 0000000000000000 ffff8800b452e338 [ 27.440086] 0000000000000000 ffff8801d0d8f908 ffffffff814fd9f3 ffff8800b452e338 [ 27.448051] Call Trace: [ 27.450610] [] dump_stack+0xc1/0x124 [ 27.455942] [] print_address_description+0x73/0x260 [ 27.462576] [] kasan_report+0x285/0x370 [ 27.468169] [] ? __lock_acquire+0x387e/0x4b50 [ 27.474284] [] __asan_report_load8_noabort+0x14/0x20 [ 27.481007] [] __lock_acquire+0x387e/0x4b50 [ 27.486948] [] ? __lock_acquire+0xb5f/0x4b50 [ 27.492974] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 27.499961] [] ? debug_check_no_locks_freed+0x2c0/0x2c0 [ 27.506945] [] ? mark_held_locks+0xaf/0x100 [ 27.512886] [] lock_acquire+0x15e/0x460 [ 27.518480] [] ? remove_wait_queue+0x14/0x40 [ 27.524509] [] _raw_spin_lock_irqsave+0x4e/0x70 [ 27.530798] [] ? remove_wait_queue+0x14/0x40 [ 27.536824] [] remove_wait_queue+0x14/0x40 [ 27.542681] [] ep_unregister_pollwait.isra.6+0xa8/0x220 [ 27.549664] [] ? ep_unregister_pollwait.isra.6+0x114/0x220 [ 27.556993] [] ? ep_free+0x1c0/0x1c0 [ 27.562324] [] ep_free+0x93/0x1c0 [ 27.567395] [] ? ep_free+0x1c0/0x1c0 [ 27.572728] [] ep_eventpoll_release+0x44/0x60 [ 27.578844] [] __fput+0x233/0x6d0 [ 27.583922] [] ____fput+0x15/0x20 [ 27.588999] [] task_work_run+0x104/0x180 [ 27.594681] [] do_exit+0x871/0x2a20 [ 27.599929] [] ? release_task+0x1240/0x1240 [ 27.605873] [] ? SyS_epoll_create+0x190/0x190 [ 27.611989] [] do_group_exit+0x108/0x320 [ 27.617678] [] ? lockdep_sys_exit_thunk+0x12/0x14 [ 27.624144] [] SyS_exit_group+0x1d/0x20 [ 27.629752] [] entry_SYSCALL_64_fastpath+0x16/0x92 [ 27.636297] [ 27.637894] Allocated by task 3318: [ 27.641487] [] save_stack_trace+0x26/0x50 [ 27.647386] [] save_stack+0x43/0xd0 [ 27.652748] [] kasan_kmalloc+0xad/0xe0 [ 27.658381] [] kmem_cache_alloc_trace+0x100/0x2b0 [ 27.664967] [] binder_get_thread+0x181/0x7a0 [ 27.671116] [] binder_poll+0x4a/0x210 [ 27.676651] [] SyS_epoll_ctl+0x10b1/0x2050 [ 27.682623] [] entry_SYSCALL_64_fastpath+0x16/0x92 [ 27.689290] [ 27.690891] Freed by task 3318: [ 27.694136] [] save_stack_trace+0x26/0x50 [ 27.700026] [] save_stack+0x43/0xd0 [ 27.705387] [] kasan_slab_free+0x72/0xc0 [ 27.711182] [] kfree+0xfc/0x300 [ 27.716200] [] binder_thread_dec_tmpref+0x1c1/0x250 [ 27.722949] [] binder_thread_release+0x27d/0x540 [ 27.729437] [] binder_ioctl+0xb94/0x12e0 [ 27.735247] [] do_vfs_ioctl+0x7aa/0xee0 [ 27.740969] [] SyS_ioctl+0x8f/0xc0 [ 27.746250] [] entry_SYSCALL_64_fastpath+0x16/0x92 [ 27.752921] [ 27.754518] The buggy address belongs to the object at ffff8800b452e280 [ 27.754518] which belongs to the cache kmalloc-512 of size 512 [ 27.767143] The buggy address is located 184 bytes inside of [ 27.767143] 512-byte region [ffff8800b452e280, ffff8800b452e480) [ 27.778985] The buggy address belongs to the page: [ 27.804981] ------------[ cut here ]------------ [ 27.809788] WARNING: CPU: 1 PID: 0 at lib/debugobjects.c:263 debug_print_object+0x17d/0x220() [ 27.818451] ODEBUG: deactivate not available (active state 0) object type: hrtimer hint: 0x8948fff8aa88e883 [ 27.828466] Kernel panic - not syncing: panic_on_warn set ... [ 27.828466] [ 27.835833] CPU: 1 PID: 0 Comm: swapper/1 Not tainted 4.4.112-g5f6325b #28 [ 27.842837] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 27.852187] 0000000000000000 24f88085db7b84d3 ffff8801db307ac8 ffffffff81d0579d [ 27.860256] ffffffff83843200 ffff8801db307ba0 ffffffff839fe0a0 0000000000000009 [ 27.868304] 0000000000000107 ffff8801db307b90 ffffffff81419e6a 0000000041b58ab3 [ 27.876342] Call Trace: [ 27.878917] [] dump_stack+0xc1/0x124 [ 27.885035] [] panic+0x1aa/0x388 [ 27.890056] [] ? percpu_up_read.constprop.45+0xe1/0xe1 [ 27.896992] [] ? warn_slowpath_common+0x10a/0x140 [ 27.903494] [] warn_slowpath_common+0x125/0x140 [ 27.909817] [] ? debug_print_object+0x17d/0x220 [ 27.916140] [] warn_slowpath_fmt+0xc1/0x110 [ 27.922118] [] ? warn_slowpath_common+0x140/0x140 [ 27.928619] [] ? ktime_add_safe+0xa0/0xa0 [ 27.934507] [] debug_print_object+0x17d/0x220 [ 27.940654] [] debug_object_deactivate+0x25d/0x3c0 [ 27.947239] [] ? debug_object_activate+0x500/0x500 [ 27.953817] [] ? dump_page_badflags+0x190/0x250 [ 27.960137] [] ? __lock_is_held+0xa1/0xf0 [ 27.965943] [] ? dump_page_badflags+0x190/0x250 [ 27.972266] [] __hrtimer_run_queues+0x492/0xfe0 [ 27.978590] [] ? hrtimer_fixup_init+0x70/0x70 [ 27.984746] [] ? hrtimer_interrupt+0x131/0x440 [ 27.990986] [] hrtimer_interrupt+0x1a6/0x440 [ 27.997049] [] local_apic_timer_interrupt+0x6a/0xb0 [ 28.003726] [] smp_apic_timer_interrupt+0x76/0xa0 [ 28.010224] [] apic_timer_interrupt+0xa0/0xb0 [ 28.016360] [] ? native_safe_halt+0x6/0x10 [ 28.023014] [] ? trace_hardirqs_on+0xd/0x10 [ 28.028988] [] default_idle+0x55/0x3c0 [ 28.034533] [] arch_cpu_idle+0xa/0x10 [ 28.039990] [] default_idle_call+0x48/0x70 [ 28.045892] [] cpu_startup_entry+0x605/0x820 [ 28.051962] [] ? call_cpuidle+0xe0/0xe0 [ 28.057592] [] ? clockevents_register_device+0x122/0x230 [ 28.064698] [] start_secondary+0x304/0x3e0 [ 28.070594] [] ? set_cpu_sibling_map+0x1040/0x1040 [ 29.196380] Shutting down cpus with NMI [ 29.201113] Dumping ftrace buffer: [ 29.204917] (ftrace buffer empty) [ 29.208604] Kernel Offset: disabled [ 29.212339] Rebooting in 86400 seconds..